Ecology and the Environment Flashcards
Define population
Species that occupies the same habitat
Define habitat
The place in which an organism lives
Define ecosystem
The interactions between the biotic and abiotic factors in an area
Define biodiversity
The variation between organisms
Gice 2 abiotic factors that affect animal population sizes
-Temperature
-Water availability
Give 2 biotic factors that affect the population size
-Number of predators
-Presence of disease and pathogens
Define community
Populations of different species interacting
Give 4 biotic factors that affect communities
-Number of predators
-Food availability
-Disease
-Human activity
What is a producer?
An organism that makes its own food
What is a primary consumer?
An organism that feeds on producers
What is a secondary consumer?
An organism that feeds on primary consumers
What is biomass
The dry mass of all the living organisms in an area
Why is dry mass used for biomass?
Because the wet mass varies as de volume of water in the organism varies
How do you calculate the efficiency of biomass transfer?
efficiency= energy transferred / total energy available x 100
Why are biomass transfers not 100% efficient?
-egestion
-Excretion
-Respiration
-The production of inedible bones and shells
How does the efficiency of biomass transfers affect the number of trophic levels in a biomass pyramid?
The less efficient the transfers, the fewer trophic levels and the fewer organisms in higher trophic levels.
Difference between a food web and a food chain?
Food webs show the interactions of multiple different food chains. Food chains show one path of food dependencies
3 molecules which are cycled through ecosystems
oxygen, carbon dioxide and water
Describe how carbon dioxide is cycled through and ecosystem
-Carbon dioxide is fixed through photosynthesis
-Respiration releases carbon dioxide
-Decomposition and waste releases carbon dioxide
-Combustion releases carbon dioxide
Describe how nitrogen is cycled through an ecosystem
-Nitrogen is fixed by lighting, the Haber process and bacteria
-Decomposers break dead matter down into ammonia
-Nitrifying bacteria convert ammonia into nitrates and nitrites
-Denitrifying bacteria release nitrogen back to the atmosphere
What impacts can sulfur dioxide have on the environment?
-Formed when fossil fuels containing impurities are burnt
-Sulfur dioxide can dissolve in water to form acid rain which can erode buildings and pollute water sources
What impacts can carbon monoxide have on the environment?
-It’s formed from the incomplete combustion of fossil fuels
-Binds irreversibly to haemoglobin which prevents it from carrying oxygen
-Too much exposure can cause unconsciousness and death
Name 5 greenhouse gases
-Water vapour
-Carbon dioxide
-Nitrous oxide
-Methane
-CFCs
Give 3 human activities that contribute to greenhouse gases
-Burning fossil fuels
-Deforestation
-Large scale livestock farming
How do greenhouse gases lead to global warming?
-Greenhouse gases allow heat from the sun to enter the atmosphere
-The gases act as a blanket and trap the heat in the atmosphere
Sate 3 negative consequences of global warming?
-Sea level rise caused by melting icebergs
-Disrupted farming and agriculture
-Increased spread of diseases in warmer climates
Describe how sewage in waterways can affect aquatic life
Microorganisms that decompose sewage will use up the oxygen in the water so that there is not enough oxygen left for respiration for other aquatic organisms
What is eutrophication?
An excess of nutrients in a body of water, often due to fertilisers in the water source
What is eutrophication bad for aquatic life?
It causes algal bloom which decreases oxygen supplies in the water and degrades the water quality. They can also block sunlight and the dead algae bring O2 consuming bacteria
5 negative effects of deforestation
-Leaching
-Less CO2 taken out of the atmosphere from photosynthesis
-Soil erosion
-Habitat disruption
-Disruption of the carbon cycle
What is leaching?
Trees usually takes up lots of nutrients. When lots of tress are cut down, these nutrients can leak out into waterways. Large quantities of nutrients in waterways can cause problems such as algal bloom.
What is evapotranspiration?
Process involving tress providing lots of water to the atmosphere from soil through evaporation and transpiration
What effect does deforestation have on evapotranspiration?
-Less trees means that there will be less evapotranspiration
-This means that less water will be returned to the atmosphere quickly
-This causes areas to dry up
